Obesity 'could protect' against respiratory distress syndromes

12th July 2011

Obesity could protect patients from developing and dying from respiratory insufficiency (RI) and adult respiratory distress syndrome (ARDS), a new report suggests.

Researchers from the Hospital for Special Surgery in New York, US, have discovered that obese adults undergoing surgery are less frequently developing RI and ARDS, and, when they do, they are less likely to have fatal outcomes.

The scientists have several theories of how obesity could protect obese patients from mortality associated with the syndromes, and establishing the protective mechanism could help develop interventions to help non-obese patients.

Researchers looked at a large national database to identify roughly nine million patients who underwent common surgical procedures, including open abdominal, hip and knee arthroplasty, spine and cardiac procedures, that are known to have a high risk of leading to RI/ARDS.

Some 5.48 per cent of these patients had a diagnosis of obesity, and the incidents of RI/ARDS was 1.82 per cent among this set, compared to 2.01 per cent among non-obese patients.

And in patients with these conditions, in-hospital mortality was significantly lower in obese patients, 5.45 per cent against 18.72 per cent.

The researchers identified several theories as to how obesity could protect against mortality in patients with RI/ARDS.

It may be that obese people have more energy stores or better nutritional status to help them get through an acute illness, and fatty tissue may have some advantageous effect in the setting of a high inflammatory state.

Another hypothesis is that doctors are often more vigilant with obese patients, because they worry they will have more health problems.

"Although the assumption is that patients with obesity have worse perioperative and long-term outcomes, this study clearly shows that in the setting of RI/ARDS, this is not the case and obesity might actually be protective in this setting," said Stavros G Memtsoudis, M.D., Ph.D., an anesthesiologist at Hospital for Special Surgery, who led the study.

The report was published online ahead of print in the Journal of Intensive Care Medicine.

Posted by Jeanette Royston

"Obese patients less likely to develop and die from respiratory distress syndromes after surgery". Journal of Intensive Care Medicine, July 11 2011.